.\"
.\" avrdude - A Downloader/Uploader for AVR device programmers
.\" Copyright (C) 2001, 2002, 2003, 2005 - 2016  Joerg Wunsch
.\"
.\" This program is free software; you can redistribute it and/or modify
.\" it under the terms of the GNU General Public License as published by
.\" the Free Software Foundation; either version 2 of the License, or
.\" (at your option) any later version.
.\"
.\" This program is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License
.\" along with this program. If not, see <http://www.gnu.org/licenses/>.
.\"
.\"
.\" $Id$
.\"
.Dd DATE February 15, 2016
.Os
.Dt AVRDUDE 1
.Sh NAME
.Nm avrdude
.Nd driver program for ``simple'' Atmel AVR MCU programmer
.Sh SYNOPSIS
.Nm
.Fl p Ar partno
.Op Fl b Ar baudrate
.Op Fl B Ar bitclock
.Op Fl c Ar programmer-id
.Op Fl C Ar config-file
.Op Fl D
.Op Fl e
.Oo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Oc
.Op Fl F
.Op Fl i Ar delay
.Op Fl n logfile
.Op Fl n
.Op Fl O
.Op Fl P Ar port
.Op Fl q
.Op Fl s
.Op Fl t
.Op Fl u
.Op Fl U Ar memtype:op:filename:filefmt
.Op Fl v
.Op Fl x Ar extended_param
.Op Fl V
.Sh DESCRIPTION
.Nm Avrdude
is a program for downloading code and data to Atmel AVR
microcontrollers.
.Nm Avrdude
supports Atmel's STK500 programmer,
Atmel's AVRISP and AVRISP mkII devices,
Atmel's STK600,
Atmel's JTAG ICE (mkI, mkII and 3, the latter two also in ISP mode),
programmers complying to AppNote AVR910 and AVR109 (including the Butterfly),
as well as a simple hard-wired
programmer connected directly to a
.Xr ppi 4
or
.Xr parport 4
parallel port, or to a standard serial port.
In the simplest case, the hardware consists just of a
cable connecting the respective AVR signal lines to the parallel port.
.Pp
The MCU is programmed in
.Em serial programming mode ,
so, for the
.Xr ppi 4
based programmer, the MCU signals
.Ql /RESET ,
.Ql SCK ,
.Ql MISO
and
.Ql MOSI
need to be connected to the parallel port.  Optionally, some otherwise
unused output pins of the parallel port can be used to supply power
for the MCU part, so it is also possible to construct a passive
stand-alone programming device.  Some status LEDs indicating the
current operating state of the programmer can be connected, and a
signal is available to control a buffer/driver IC 74LS367 (or
74HCT367).  The latter can be useful to decouple the parallel port
from the MCU when in-system programming is used.
.Pp
A number of equally simple bit-bang programming adapters that connect
to a serial port are supported as well, among them the popular
Ponyprog serial adapter, and the DASA and DASA3 adapters that used to
be supported by uisp(1).
Note that these adapters are meant to be attached to a physical serial
port.
Connecting to a serial port emulated on top of USB is likely to not
work at all, or to work abysmally slow.
.Pp
If you happen to have a Linux system with at least 4 hardware GPIOs 
available (like almost all embedded Linux boards) you can do without 
any additional hardware - just connect them to the MOSI, MISO, RESET 
and SCK pins on the AVR and use the linuxgpio programmer type. It bitbangs
the lines using the Linux sysfs GPIO interface. Of course, care should
be taken about voltage level compatibility. Also, although not strictrly 
required, it is strongly advisable to protect the GPIO pins from 
overcurrent situations in some way. The simplest would be to just put
some resistors in series or better yet use a 3-state buffer driver like
the 74HC244. Have a look at http://kolev.info/avrdude-linuxgpio for a more
detailed tutorial about using this programmer type.
.Pp
Atmel's STK500 programmer is also supported and connects to a serial
port.
Both, firmware versions 1.x and 2.x can be handled, but require a
different programmer type specification (by now).
Using firmware version 2, high-voltage programming is also supported,
both parallel and serial
(programmer types stk500pp and stk500hvsp).
.Pp
Wiring boards are supported, utilizing STK500 V2.x protocol, but
a simple DTR/RTS toggle is used to set the boards into programming mode.
The programmer type is ``wiring''.
.Pp
The Arduino (which is very similar to the STK500 1.x) is supported via
its own programmer type specification ``arduino''.
.Pp
The BusPirate is a versatile tool that can also be used as an AVR programmer.
A single BusPirate can be connected to up to 3 independent AVRs. See
the section on
.Em extended parameters
below for details.
.Pp
Atmel's STK600 programmer is supported in ISP and high-voltage
programming modes, and connects through the USB.
For ATxmega devices, the STK600 is supported in PDI mode.
For ATtiny4/5/9/10 devices, the STK600 and AVRISP mkII are supported in TPI mode.
.Pp
The simple serial programmer described in Atmel's application note
AVR910, and the bootloader described in Atmel's application note
AVR109 (which is also used by the AVR Butterfly evaluation board), are
supported on a serial port.
.Pp
Atmel's JTAG ICE (mkI, mkII, and 3) is supported as well to up- or download memory
areas from/to an AVR target (no support for on-chip debugging).
For the JTAG ICE mkII, JTAG, debugWire and ISP mode are supported, provided
it has a firmware revision of at least 4.14 (decimal).
JTAGICE3 also supports all of JTAG, debugWIRE, and ISP mode.
See below for the limitations of debugWire.
For ATxmega devices, the JTAG ICE mkII is supported in PDI mode, provided it
has a revision 1 hardware and firmware version of at least 5.37 (decimal).
For ATxmega devices, the JTAGICE3 is supported in PDI mode.
.Pp
Atmel-ICE (ARM/AVR) is supported in all modes (JTAG, PDI for Xmega, debugWIRE,
ISP).
.Pp
Atmel's XplainedPro boards, using the EDBG protocol (CMSIS-DAP compatible),
are supported using the "jtag3" programmer type.
.Pp
Atmel's XplainedMini boards, using the mEDBG protocol,
are also supported using the "jtag3" programmer type.
.Pp
The AVR Dragon is supported in all modes (ISP, JTAG, HVSP, PP, debugWire).
When used in JTAG and debugWire mode, the AVR Dragon behaves similar to a
JTAG ICE mkII, so all device-specific comments for that device
will apply as well.
When used in ISP mode, the AVR Dragon behaves similar to an
AVRISP mkII (or JTAG ICE mkII in ISP mode), so all device-specific
comments will apply there.
In particular, the Dragon starts out with a rather fast ISP clock
frequency, so the
.Fl B Ar bitclock
option might be required to achieve a stable ISP communication.
For ATxmega devices, the AVR Dragon is supported in PDI mode, provided it
has a firmware version of at least 6.11 (decimal).
.Pp
The avrftdi, USBasp ISP and USBtinyISP adapters are also supported, provided
.Nm avrdude
has been compiled with libusb support.
USBasp ISP and USBtinyISP both feature simple firmware-only USB implementations, 
running on an ATmega8 (or ATmega88), or ATtiny2313, respectively. If libftdi has 
has been compiled in 
.Nm avrdude ,
the avrftdi device adds support for many programmers using FTDI's 2232C/D/H 
and 4232H parts running in MPSSE mode, which hard-codes (in the chip) 
SCK to bit 1, MOSI to bit 2, and MISO to bit 3. Reset is usually bit 4.
.Pp
The Atmel DFU bootloader is supported in both, FLIP protocol version 1
(AT90USB* and ATmega*U* devices), as well as version 2 (Xmega devices).
See below for some hints about FLIP version 1 protocol behaviour.
.Pp
Input files can be provided, and output files can be written in
different file formats, such as raw binary files containing the data
to download to the chip, Intel hex format, or Motorola S-record
format.  There are a number of tools available to produce those files,
like
.Xr asl 1
as a standalone assembler, or
.Xr avr-objcopy 1
for the final stage of the GNU toolchain for the AVR microcontroller.
.Pp
Provided
.Xr libelf 3
was present when compiling
.Nm avrdude ,
the input file can also be the final ELF file as produced by the linker.
The appropriate ELF section(s) will be examined, according to the memory
area to write to.
.Pp
.Nm Avrdude
can program the EEPROM and flash ROM memory cells of supported AVR
parts.  Where supported by the serial instruction set, fuse bits and
lock bits can be programmed as well.  These are implemented within
.Nm
as separate memory types and can be programmed using data from a file
(see the
.Fl m
option) or from terminal mode (see the
.Ar dump
and
.Ar write
commands).  It is also possible to read the chip (provided it has not
been code-protected previously, of course) and store the data in a
file.  Finally, a ``terminal'' mode is available that allows one to
interactively communicate with the MCU, and to display or program
individual memory cells.
On the STK500 and STK600 programmer, several operational parameters (target supply
voltage, target Aref voltage, master clock) can be examined and changed
from within terminal mode as well.
.Ss Options
In order to control all the different operation modi, a number of options
need to be specified to
.Nm avrdude .
.Bl -tag -offset indent -width indent
.It Fl p Ar partno
This is the only option that is mandatory for every invocation of
.Nm avrdude .
It specifies the type of the MCU connected to the programmer.  These are read from the config file.
For currently supported MCU types use ? as partno, this will print a list of partno ids and official part names on the terminal. (Both can be used with the -p option.)
.Pp
Following parts need special attention:
.Bl -tag -width "ATmega1234"
.It "AT90S1200"
The ISP programming protocol of the AT90S1200 differs in subtle ways
from that of other AVRs.  Thus, not all programmers support this
device.  Known to work are all direct bitbang programmers, and all
programmers talking the STK500v2 protocol.
.It "AT90S2343"
The AT90S2323 and ATtiny22 use the same algorithm.
.It "ATmega2560, ATmega2561"
Flash addressing above 128 KB is not supported by all
programming hardware.  Known to work are jtag2, stk500v2,
and bit-bang programmers.
.It "ATtiny11"
The ATtiny11 can only be
programmed in high-voltage serial mode.
.El
.It Fl b Ar baudrate
Override the RS-232 connection baud rate specified in the respective
programmer's entry of the configuration file.
.It Fl B Ar bitclock
Specify the bit clock period for the JTAG interface or the ISP clock (JTAG ICE only).
The value is a floating-point number in microseconds.
Alternatively, the value might be suffixed with "Hz", "kHz", or "MHz",
in order to specify the bit clock frequency, rather than a period.
The default value of the JTAG ICE results in about 1 microsecond bit
clock period, suitable for target MCUs running at 4 MHz clock and
above.
Unlike certain parameters in the STK500, the JTAG ICE resets all its
parameters to default values when the programming software signs
off from the ICE, so for MCUs running at lower clock speeds, this
parameter must be specified on the command-line.
You can use the 'default_bitclock' keyword in your
.Pa ${HOME}/.avrduderc
file to assign a default value to keep from having to specify this
option on every invocation.
.It Fl c Ar programmer-id
Use the programmer specified by the argument.  Programmers and their pin
configurations are read from the config file (see the
.Fl C
option).  New pin configurations can be easily added or modified
through the use of a config file to make
.Nm avrdude
work with different programmers as long as the programmer supports the
Atmel AVR serial program method.  You can use the 'default_programmer'
keyword in your
.Pa ${HOME}/.avrduderc
file to assign a default programmer to keep from having to specify
this option on every invocation.
A full list of all supported programmers is output to the terminal 
by using ? as programmer-id.
.It Fl C Ar config-file
Use the specified config file to load configuration data.  This file
contains all programmer and part definitions that
.Nm avrdude
knows about.
See the config file, located at
.Pa ${PREFIX}/etc/avrdude.conf ,
which contains a description of the format.
.Pp
If 
.Ar config-file
is written as
.Pa +filename
then this file is read after the system wide and user configuration
files. This can be used to add entries to the configuration
without patching your system wide configuration file. It can be used
several times, the files are read in same order as given on the command
line.
.It Fl D
Disable auto erase for flash.  When the
.Fl U
option with flash memory is specified,
.Nm
will perform a chip erase before starting any of the programming
operations, since it generally is a mistake to program the flash
without performing an erase first.  This option disables that.
Auto erase is not used for ATxmega devices as these devices can
use page erase before writing each page so no explicit chip erase
is required.
Note however that any page not affected by the current operation
will retain its previous contents.
.It Fl e
Causes a chip erase to be executed.  This will reset the contents of the
flash ROM and EEPROM to the value
.Ql 0xff ,
and clear all lock bits.
Except for ATxmega devices which can use page erase,
it is basically a prerequisite command before the flash ROM can be
reprogrammed again.  The only exception would be if the new
contents would exclusively cause bits to be programmed from the value
.Ql 1
to
.Ql 0 .
Note that in order to reprogram EERPOM cells, no explicit prior chip
erase is required since the MCU provides an auto-erase cycle in that
case before programming the cell.
.It Xo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Xc
By default,
.Nm
leaves the parallel port in the same state at exit as it has been
found at startup.  This option modifies the state of the
.Ql /RESET
and
.Ql Vcc
lines the parallel port is left at, according to the
.Ar exitspec
arguments provided, as follows:
.Bl -tag -width noreset
.It Ar reset
The
.Ql /RESET
signal will be left activated at program exit, that is it will be held
.Em low ,
in order to keep the MCU in reset state afterwards.  Note in particular
that the programming algorithm for the AT90S1200 device mandates that
the
.Ql /RESET
signal is active
.Em before
powering up the MCU, so in case an external power supply is used for this
MCU type, a previous invocation of
.Nm
with this option specified is one of the possible ways to guarantee this
condition.
.It Ar noreset
The
.Ql /RESET
line will be deactivated at program exit, thus allowing the MCU target
program to run while the programming hardware remains connected.
.It Ar vcc
This option will leave those parallel port pins active
.Pq \&i. \&e. Em high
that can be used to supply
.Ql Vcc
power to the MCU.
.It Ar novcc
This option will pull the
.Ql Vcc
pins of the parallel port down at program exit.
.It Ar d_high
This option will leave the 8 data pins on the parallel port active.
.Pq \&i. \&e. Em high
.It Ar d_low
This option will leave the 8 data pins on the parallel port inactive.
.Pq \&i. \&e. Em low
.El
.Pp
Multiple
.Ar exitspec
arguments can be separated with commas.
.It Fl F
Normally,
.Nm
tries to verify that the device signature read from the part is
reasonable before continuing.  Since it can happen from time to time
that a device has a broken (erased or overwritten) device signature
but is otherwise operating normally, this options is provided to
override the check.
Also, for programmers like the Atmel STK500 and STK600 which can
adjust parameters local to the programming tool (independent of an
actual connection to a target controller), this option can be used
together with
.Fl t
to continue in terminal mode.
.It Fl i Ar delay
For bitbang-type programmers, delay for approximately
.Ar delay
microseconds between each bit state change.
If the host system is very fast, or the target runs off a slow clock
(like a 32 kHz crystal, or the 128 kHz internal RC oscillator), this
can become necessary to satisfy the requirement that the ISP clock
frequency must not be higher than 1/4 of the CPU clock frequency.
This is implemented as a spin-loop delay to allow even for very
short delays.
On Unix-style operating systems, the spin loop is initially calibrated
against a system timer, so the number of microseconds might be rather
realistic, assuming a constant system load while
.Nm
is running.
On Win32 operating systems, a preconfigured number of cycles per
microsecond is assumed that might be off a bit for very fast or very
slow machines.
.It Fl l Ar logfile
Use
.Ar logfile
rather than
.Va stderr
for diagnostics output.
Note that initial diagnostic messages (during option parsing) are still
written to
.Va stderr
anyway.
.It Fl n
No-write - disables actually writing data to the MCU (useful for debugging
.Nm avrdude
).
.It Fl O
Perform a RC oscillator run-time calibration according to Atmel
application note AVR053.
This is only supported on the STK500v2, AVRISP mkII, and JTAG ICE mkII
hardware.
Note that the result will be stored in the EEPROM cell at address 0.
.It Fl P Ar port
Use
.Ar port
to identify the device to which the programmer is attached.  By
default the
.Pa /dev/ppi0
port is used, but if the programmer type normally connects to the
serial port, the
.Pa /dev/cuaa0
port is the default.  If you need to use a different parallel or
serial port, use this option to specify the alternate port name.
.Pp
On Win32 operating systems, the parallel ports are referred to as lpt1
through lpt3, referring to the addresses 0x378, 0x278, and 0x3BC,
respectively.  If the parallel port can be accessed through a different
address, this address can be specified directly, using the common C
language notation (i. e., hexadecimal values are prefixed by
.Ql 0x
).
.Pp
For the JTAG ICE mkII and JTAGICE3, if
.Nm
has been configured with libusb support,
.Ar port
can alternatively be specified as
.Pa usb Ns Op \&: Ns Ar serialno .
This will cause
.Nm
to search the programmer on USB.
If
.Ar serialno
is also specified, it will be matched against the serial number read
from any JTAG ICE mkII found on USB.
The match is done after stripping any existing colons from the given
serial number, and right-to-left, so only the least significant bytes
from the serial number need to be given.
.Pp
As the AVRISP mkII device can only be talked to over USB, the very
same method of specifying the port is required there.
.Pp
For the USB programmer "AVR-Doper" running in HID mode, the port must
be specified as
.Ar avrdoper.
Libusb support is required on Unix but not on Windows. For more
information about AVR-Doper see http://www.obdev.at/avrusb/avrdoper.html.
.Pp
For the USBtinyISP, which is a simplicistic device not implementing
serial numbers, multiple devices can be distinguished by their
location in the USB hierarchy.  See the the respective
.Em Troubleshooting
entry in the detailed documentation for examples.
.Pp
For programmers that attach to a serial port using some kind of
higher level protocol (as opposed to bit-bang style programmers),
.Ar port
can be specified as
.Pa net Ns \&: Ns Ar host Ns \&: Ns Ar port .
In this case, instead of trying to open a local device, a TCP
network connection to (TCP)
.Ar port
on
.Ar host
is established.
Square brackets may be placed around
.Ar host
to improve readability, for numeric IPv6 addresses (e.g.
.Li net:[2001:db8::42]:1337 ) .
The remote endpoint is assumed to be a terminal or console server
that connects the network stream to a local serial port where the
actual programmer has been attached to.
The port is assumed to be properly configured, for example using a
transparent 8-bit data connection without parity at 115200 Baud
for a STK500.
.Pp
Note: The ability to handle IPv6 hostnames and addresses is limited to
Posix systems (by now).
.It Fl q
Disable (or quell) output of the progress bar while reading or writing
to the device.  Specify it a second time for even quieter operation.
.It Fl s
Disable safemode prompting.  When safemode discovers that one or more
fuse bits have unintentionally changed, it will prompt for
confirmation regarding whether or not it should attempt to recover the
fuse bit(s).  Specifying this flag disables the prompt and assumes
that the fuse bit(s) should be recovered without asking for
confirmation first.
.It Fl t
Tells
.Nm
to enter the interactive ``terminal'' mode instead of up- or downloading
files.  See below for a detailed description of the terminal mode.
.It Fl u
Disable the safemode fuse bit checks.  Safemode is enabled by default
and is intended to prevent unintentional fuse bit changes.  When
enabled, safemode will issue a warning if the any fuse bits are found
to be different at program exit than they were when
.Nm
was invoked.  Safemode won't alter fuse bits itself, but rather will
prompt for instructions, unless the terminal is non-interactive, in
which case safemode is disabled.  See the
.Fl s
option to disable safemode prompting.
.Pp
If one of the configuration files has a line
.Dl "default_safemode = no;"
safemode is disabled by default.
The
.Fl u
option's effect is negated in that case, i. e. it
.Em enables
safemode.
.Pp
Safemode is always disabled for AVR32, Xmega and TPI devices.
.It Xo Fl U Ar memtype Ns
.Ar \&: Ns Ar op Ns
.Ar \&: Ns Ar filename Ns
.Op \&: Ns Ar format
.Xc
Perform a memory operation as indicated.  The
.Ar memtype
field specifies the memory type to operate on.
The available memory types are device-dependent, the actual
configuration can be viewed with the
.Cm part
command in terminal mode.
Typically, a device's memory configuration at least contains
the memory types
.Ar flash
and
.Ar eeprom .
All memory types currently known are:
.Bl -tag -width "calibration" -compact
.It calibration
One or more bytes of RC oscillator calibration data.
.It eeprom
The EEPROM of the device.
.It efuse
The extended fuse byte.
.It flash
The flash ROM of the device.
.It fuse
The fuse byte in devices that have only a single fuse byte.
.It hfuse
The high fuse byte.
.It lfuse
The low fuse byte.
.It lock
The lock byte.
.It signature
The three device signature bytes (device ID).
.It fuse Ns Em N
The fuse bytes of ATxmega devices,
.Em N
is an integer number
for each fuse supported by the device.
.It application
The application flash area of ATxmega devices.
.It apptable
The application table flash area of ATxmega devices.
.It boot
The boot flash area of ATxmega devices.
.It prodsig
The production signature (calibration) area of ATxmega devices.
.It usersig
The user signature area of ATxmega devices.
.El
.Pp
The
.Ar op
field specifies what operation to perform:
.Bl -tag -width noreset
.It Ar r
read device memory and write to the specified file
.It Ar w
read data from the specified file and write to the device memory
.It Ar v
read data from both the device and the specified file and perform a verify
.El
.Pp
The
.Ar filename
field indicates the name of the file to read or write.
The
.Ar format
field is optional and contains the format of the file to read or
write.
.Ar Format
can be one of:
.Bl -tag -width sss
.It Ar i
Intel Hex
.It Ar s
Motorola S-record
.It Ar r
raw binary; little-endian byte order, in the case of the flash ROM data
.It Ar e
ELF (Executable and Linkable Format)
.It Ar m
immediate; actual byte values specified on the command line, separated
by commas or spaces.  This is good for programming fuse bytes without
having to create a single-byte file or enter terminal mode.
.It Ar a
auto detect; valid for input only, and only if the input is not
provided at
.Em stdin .
.It Ar d
decimal; this and the following formats are only valid on output.
They generate one line of output for the respective memory section,
forming a comma-separated list of the values.
This can be particularly useful for subsequent processing, like for
fuse bit settings.
.It Ar h
hexadecimal; each value will get the string
.Em 0x
prepended.
.It Ar o
octal; each value will get a
.Em 0
prepended unless it is less than 8 in which case it gets no prefix.
.It Ar b
binary; each value will get the string
.Em 0b
prepended.
.El
.Pp
The default is to use auto detection for input files, and raw binary
format for output files.
Note that if
.Ar filename
contains a colon, the
.Ar format
field is no longer optional since the filename part following the colon
would otherwise be misinterpreted as
.Ar format .
.Pp
When reading any kind of flash memory area (including the various sub-areas
in Xmega devices), the resulting output file will be truncated to not contain
trailing 0xFF bytes which indicate unprogrammed (erased) memory.
Thus, if the entire memory is unprogrammed, this will result in an output
file that has no contents at all.
.Pp
As an abbreviation, the form
.Fl U Ar filename
is equivalent to specifying
.Fl U Em flash:w: Ns Ar filename Ns :a .
This will only work if
.Ar filename
does not have a colon in it.
.It Fl v
Enable verbose output.
More
.Fl v
options increase verbosity level.
.It Fl V
Disable automatic verify check when uploading data.
.It Fl x Ar extended_param
Pass
.Ar extended_param
to the chosen programmer implementation as an extended parameter.
The interpretation of the extended parameter depends on the
programmer itself.
See below for a list of programmers accepting extended parameters.
.El
.Ss Terminal mode
In this mode,
.Nm
only initializes communication with the MCU, and then awaits user
commands on standard input.  Commands and parameters may be
abbreviated to the shortest unambiguous form.  Terminal mode provides
a command history using
.Xr readline 3 ,
so previously entered command lines can be recalled and edited.  The
following commands are currently implemented:
.Bl -tag -offset indent -width indent
.It Ar dump memtype addr nbytes
Read
.Ar nbytes
bytes from the specified memory area, and display them in the usual
hexadecimal and ASCII form.
.It Ar dump
Continue dumping the memory contents for another
.Ar nbytes
where the previous
.Ar dump
command left off.
.It Ar write memtype addr byte1 ... byteN
Manually program the respective memory cells, starting at address
.Ar addr ,
using the values
.Ar byte1
through
.Ar byteN .
This feature is not implemented for bank-addressed memories such as
the flash memory of ATMega devices.
.It Ar erase
Perform a chip erase.
.It Ar send b1 b2 b3 b4
Send raw instruction codes to the AVR device.  If you need access to a
feature of an AVR part that is not directly supported by
.Nm ,
this command allows you to use it, even though
.Nm
does not implement the command. When using direct SPI mode, up to 3 bytes
can be omitted.
.It Ar sig
Display the device signature bytes.
.It Ar spi
Enter direct SPI mode.  The
.Em pgmled
pin acts as slave select.
.Em Only supported on parallel bitbang programmers.
.It Ar part
Display the current part settings and parameters.  Includes chip
specific information including all memory types supported by the
device, read/write timing, etc.
.It Ar pgm
Return to programming mode (from direct SPI mode).
.It Ar vtarg voltage
Set the target's supply voltage to
.Ar voltage
Volts.
.Em Only supported on the STK500 and STK600 programmer.
.It Ar varef Oo Ar channel Oc Ar voltage
Set the adjustable voltage source to
.Ar voltage
Volts.
This voltage is normally used to drive the target's
.Em Aref
input on the STK500.
On the Atmel STK600, two reference voltages are available, which
can be selected by the optional
.Ar channel
argument (either 0 or 1).
.Em Only supported on the STK500 and STK600 programmer.
.It Ar fosc freq Ns Op M Ns \&| Ns k
Set the master oscillator to
.Ar freq
Hz.
An optional trailing letter
.Ar \&M
multiplies by 1E6, a trailing letter
.Ar \&k
by 1E3.
.Em Only supported on the STK500 and STK600 programmer.
.It Ar fosc off
Turn the master oscillator off.
.Em Only supported on the STK500 and STK600 programmer.
.It Ar sck period
.Em STK500 and STK600 programmer only:
Set the SCK clock period to
.Ar period
microseconds.
.Pp
.Em JTAG ICE only:
Set the JTAG ICE bit clock period to
.Ar period
microseconds.
Note that unlike STK500 settings, this setting will be reverted to
its default value (approximately 1 microsecond) when the programming
software signs off from the JTAG ICE.
This parameter can also be used on the JTAG ICE mkII, JTAGICE3, and Atmel-ICE to specify the
ISP clock period when operating the ICE in ISP mode.
.It Ar parms
.Em STK500 and STK600 programmer only:
Display the current voltage and master oscillator parameters.
.Pp
.Em JTAG ICE only:
Display the current target supply voltage and JTAG bit clock rate/period.
.It Ar verbose Op Ar level
Change (when
.Ar level
is provided), or display the verbosity level.
The initial verbosity level is controlled by the number of
.Fl v
options given on the commandline.
.It Ar \&?
.It Ar help
Give a short on-line summary of the available commands.
.It Ar quit
Leave terminal mode and thus
.Nm avrdude .
.El
.Ss Default Parallel port pin connections
(these can be changed, see the
.Fl c
option)
.TS
ll.
\fBPin number\fP	\fBFunction\fP
2-5	Vcc (optional power supply to MCU)
7	/RESET (to MCU)
8	SCK (to MCU)
9	MOSI (to MCU)
10	MISO (from MCU)
18-25	GND
.TE
.Ss debugWire limitations
The debugWire protocol is Atmel's proprietary one-wire (plus ground)
protocol to allow an in-circuit emulation of the smaller AVR devices,
using the
.Ql /RESET
line.
DebugWire mode is initiated by activating the
.Ql DWEN
fuse, and then power-cycling the target.
While this mode is mainly intended for debugging/emulation, it
also offers limited programming capabilities.
Effectively, the only memory areas that can be read or programmed
in this mode are flash ROM and EEPROM.
It is also possible to read out the signature.
All other memory areas cannot be accessed.
There is no
.Em chip erase
functionality in debugWire mode; instead, while reprogramming the
flash ROM, each flash ROM page is erased right before updating it.
This is done transparently by the JTAG ICE mkII (or AVR Dragon).
The only way back from debugWire mode is to initiate a special
sequence of commands to the JTAG ICE mkII (or AVR Dragon), so the
debugWire mode will be temporarily disabled, and the target can
be accessed using normal ISP programming.
This sequence is automatically initiated by using the JTAG ICE mkII
or AVR Dragon in ISP mode, when they detect that ISP mode cannot be
entered.
.Ss FLIP version 1 idiosyncrasies
Bootloaders using the FLIP protocol version 1 experience some very
specific behaviour.
.Pp
These bootloaders have no option to access memory areas other than
Flash and EEPROM.
.Pp
When the bootloader is started, it enters a
.Em security mode
where the only acceptable access is to query the device configuration
parameters (which are used for the signature on AVR devices).
The only way to leave this mode is a
.Em chip erase .
As a chip erase is normally implied by the
.Fl U
option when reprogramming the flash, this peculiarity might not be
very obvious immediately.
.Pp
Sometimes, a bootloader with security mode already disabled seems to
no longer respond with sensible configuration data, but only 0xFF for
all queries.
As these queries are used to obtain the equivalent of a signature,
.Nm
can only continue in that situation by forcing the signature check
to be overridden with the
.Fl F
option.
.Pp
A
.Em chip erase
might leave the EEPROM unerased, at least on some
versions of the bootloader.
.Ss Programmers accepting extended parameters
.Bl -tag -offset indent -width indent
.It Ar JTAG ICE mkII
.It Ar JTAGICE3
.It Ar Atmel-ICE
.It Ar AVR Dragon
When using the JTAG ICE mkII, JTAGICE3, Atmel-ICE or AVR Dragon in JTAG mode, the
following extended parameter is accepted:
.Bl -tag -offset indent -width indent
.It Ar jtagchain=UB,UA,BB,BA
Setup the JTAG scan chain for
.Ar UB
units before,
.Ar UA
units after,
.Ar BB
bits before, and
.Ar BA
bits after the target AVR, respectively.
Each AVR unit within the chain shifts by 4 bits.
Other JTAG units might require a different bit shift count.
.El
.It Ar AVR910
.Bl -tag -offset indent -width indent
.It Ar devcode=VALUE
Override the device code selection by using
.Ar VALUE
as the device code.
The programmer is not queried for the list of supported
device codes, and the specified
.Ar VALUE
is not verified but used directly within the
.Ql T
command sent to the programmer.
.Ar VALUE
can be specified using the conventional number notation of the
C programming language.
.El
.Bl -tag -offset indent -width indent
.It Ar no_blockmode
Disables the default checking for block transfer capability.
Use 
.Ar no_blockmode
only if your
.Ar AVR910
programmer creates errors during initial sequence. 
.El
.It Ar buspirate
.Bl -tag -offset indent -width indent
.It Ar reset={cs,aux,aux2}
The default setup assumes the BusPirate's CS output pin connected to 
the RESET pin on AVR side. It is however possible to have multiple AVRs
connected to the same BP with MISO, MOSI and SCK lines common for all of them.
In such a case one AVR should have its RESET connected to BusPirate's
.Pa CS
pin, second AVR's RESET connected to BusPirate's
.Pa AUX
pin and if your BusPirate has an
.Pa AUX2
pin (only available on BusPirate version v1a with firmware 3.0 or newer)
use that to activate RESET on the third AVR.
.Pp
It may be a good idea to decouple the BusPirate and the AVR's SPI buses from 
each other using a 3-state bus buffer. For example 74HC125 or 74HC244 are some
good candidates with the latches driven by the appropriate reset pin (cs, 
aux or aux2). Otherwise the SPI traffic in one active circuit may interfere
with programming the AVR in the other design.
.It Ar spifreq=<0..7>
The SPI speed for the Bus Pirate's binary SPI mode:
.Bd -literal
0 ..  30 kHz   (default)
1 .. 125 kHz
2 .. 250 kHz
3 ..   1 MHz
4 ..   2 MHz
5 ..   2.6 MHz
6 ..   4 MHz
7 ..   8 MHz
.Ed
.It Ar rawfreq=<0..3>
Sets the SPI speed and uses the Bus Pirate's binary "raw-wire" mode:
.Bd -literal
0 ..   5 kHz
1 ..  50 kHz
2 .. 100 kHz   (Firmware v4.2+ only)
3 .. 400 kHz   (v4.2+)
.Ed
.Pp
The only advantage of the "raw-wire" mode is the different SPI frequencies
available. Paged writing is not implemented in this mode.
.It Ar ascii
Attempt to use ASCII mode even when the firmware supports BinMode (binary
mode). 
BinMode is supported in firmware 2.7 and newer, older FW's either don't
have BinMode or their BinMode is buggy. ASCII mode is slower and makes 
the above
.Ar reset= , spifreq=
and 
.Ar rawfreq=
parameters unavailable. Be aware that ASCII mode is not guaranteed to work
with newer firmware versions, and is retained only to maintain compatibility
with older firmware versions.
.It Ar nopagedwrite
Firmware versions 5.10 and newer support a binary mode SPI command that enables
whole pages to be written to AVR flash memory at once, resulting in a
significant write speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar nopagedread
Newer firmware versions support in binary mode SPI command some AVR Extended 
Commands. Using the "Bulk Memory Read from Flash" results in a
significant read speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar cpufreq=<125..4000>
This sets the AUX pin to output a frequency of 
.Ar n
kHz. Connecting
the AUX pin to the XTAL1 pin of your MCU, you can provide it a clock, 
for example when it needs an external clock because of wrong fuses settings.
Make sure the CPU frequency is at least four times the SPI frequency.  
.It Ar serial_recv_timeout=<1...>
This sets the serial receive timeout to the given value. 
The timeout happens every time avrdude waits for the BusPirate prompt. 
Especially in ascii mode this happens very often, so setting a smaller value 
can speed up programming a lot. 
The default value is 100ms. Using 10ms might work in most cases. 
.El
.It Ar Wiring
When using the Wiring programmer type, the
following optional extended parameter is accepted:
.Bl -tag -offset indent -width indent
.It Ar snooze=<0..32767>
After performing the port open phase, AVRDUDE will wait/snooze for
.Ar snooze
milliseconds before continuing to the protocol sync phase.
No toggling of DTR/RTS is performed if
.Ar snooze
is greater than 0.
.El
.It Ar PICkit2
Connection to the PICkit2 programmer:
.Bd -literal
(AVR)    (PICkit2)
RST  -   VPP/MCLR (1) 
VDD  -   VDD Target (2) -- possibly optional if AVR self powered 
GND  -   GND (3) 
MISO -   PGD (4) 
SCLK -   PDC (5) 
MOSI -   AUX (6) 

.Ed
Extended commandline parameters:
.Bl -tag -offset indent -width indent
.It Ar clockrate=<rate>
Sets the SPI clocking rate in Hz (default is 100kHz). Alternately the -B or -i options can be used to set the period.
.It Ar timeout=<usb-transaction-timeout>
Sets the timeout for USB reads and writes in milliseconds (default is 1500 ms).
.El
.El
.Sh FILES
.Bl -tag -offset indent -width /dev/ppi0XXX
.It Pa /dev/ppi0
default device to be used for communication with the programming
hardware
.It Pa ${PREFIX}/etc/avrdude.conf
programmer and parts configuration file
.It Pa ${HOME}/.avrduderc
programmer and parts configuration file (per-user overrides)
.It Pa ~/.inputrc
Initialization file for the
.Xr readline 3
library
.It Pa ${PREFIX}/share/doc/avrdude/avrdude.pdf
Schematic of programming hardware
.El
.\" .Sh EXAMPLES
.Sh DIAGNOSTICS
.Bd -literal
avrdude: jtagmkII_setparm(): bad response to set parameter command: RSP_FAILED
avrdude: jtagmkII_getsync(): ISP activation failed, trying debugWire
avrdude: Target prepared for ISP, signed off.
avrdude: Please restart avrdude without power-cycling the target.
.Ed
.Pp
If the target AVR has been set up for debugWire mode (i. e. the
.Em DWEN
fuse is programmed), normal ISP connection attempts will fail as
the
.Em /RESET
pin is not available.
When using the JTAG ICE mkII in ISP mode, the message shown indicates
that
.Nm
has guessed this condition, and tried to initiate a debugWire reset
to the target.
When successful, this will leave the target AVR in a state where it
can respond to normal ISP communication again (until the next power
cycle).
Typically, the same command is going to be retried again immediately
afterwards, and will then succeed connecting to the target using
normal ISP communication.
.Sh SEE ALSO
.Xr avr-objcopy 1 ,
.Xr ppi 4 ,
.Xr libelf 3,
.Xr readline 3
.Pp
The AVR microcontroller product description can be found at
.Pp
.Dl "http://www.atmel.com/products/AVR/"
.\" .Sh HISTORY
.Sh AUTHORS
.Nm Avrdude
was written by Brian S. Dean <bsd@bsdhome.com>.
.Pp
This man page by
.ie t J\(:org Wunsch.
.el Joerg Wunsch.
.Sh BUGS
Please report bugs via
.Dl "http://savannah.nongnu.org/bugs/?group=avrdude" .
.Pp
The JTAG ICE programmers currently cannot write to the flash ROM
one byte at a time.
For that reason, updating the flash ROM from terminal mode does not
work.
.Pp
Page-mode programming the EEPROM through JTAG (i.e. through an
.Fl U
option) requires a prior chip erase.
This is an inherent feature of the way JTAG EEPROM programming works.
This also applies to the STK500 and STK600 in parallel programming mode.
.Pp
The USBasp and USBtinyISP drivers do not offer any option to distinguish multiple
devices connected simultaneously, so effectively only a single device
is supported.
.Pp
The avrftdi driver allows one to select specific devices using any combination of vid,pid
serial number (usbsn) vendor description (usbvendoror part description (usbproduct)
as seen with lsusb or whatever tool used to view USB device information. Multiple 
devices can be on the bus at the same time. For the H parts, which have multiple MPSSE
interfaces, the interface can also be selected.  It defaults to interface 'A'.
